But if you go to the ESPN site for each game you can see the play by play. You should go check those. Just like witnesses at a crime scene have problem with memory, you are suffering from some cognitive dissonance in what you remember. The actual play by play disproves your memory.
BYU had the 10th best rushing attack in the country last year with arguably the toughest schedule in BYU history. Every back averaged 5 yards or more a carry except Brown who averaged 4.9. Those "dives" you talk about are a read...and if you only run outside with some backs and only run inside with other backs...how hard is that to pick up for a DC?
Do a little study of the play by play and the stats and get back to us.